Intraoperative cerebral angiography reveals microsurgically occult sequelae of temporary clip application during elective cerebral aneurysm surgery

Background: Temporary clipping (TC) is an essential adjunct in cerebral aneurysm (CA) surgery. Despite appearing insignificant to the surgeon under the microscope, TC may cause parent vessel injury. Intraoperative diagnostic cerebral angiography (ioDCA) is crucial for assessing aneurysm occlusion and parent vessel integrity. We aimed to assess sequelae of TC evident on immediate ioDCA.

Methods: Elective CA clippings with ioDCA in a hybrid operating room from January 2020 to June 2023 were reviewed. Microsurgical and angiographic assessments were performed to identify post-TC parent vessel alterations. Outcomes were compared between TC and non-TC-groups.

Results: Collectively, 107 patients underwent 111 craniotomies for clipping of 127 CAs. TC was used in 59/111 cases (53.2%) for treatment of 66/127 CAs (51.9%). CA size and neck were significantly larger in the TC group than in the non-TC group (p<0.001). Parent vessel vasospasm at the site of the previous temporary clip location was evident on 3D rotational angiography in 12/59 (20.3%) TC cases. Clip adjustment rates after ioDCA were similar between groups (TC 13.6% vs non-TC 8.2%, p=0.328). In the TC group compared with the non-TC group, the rates of symptomatic radiographic ischemia and functional decline at discharge were significantly higher (p=0.022 and p=0.045, respectively). However, functional status at follow-up was comparable (p=0.620).

Conclusions: TC during CA surgery can cause significant yet microsurgically occult vasospasm in the parent vessel, potentially contributing to symptomatic ischemia and early functional decline. Intraoperative angiography is crucial for detecting this issue, highlighting both its importance and the risks associated with TC.